A user puts on a cap to (for example) protect the user's face from sunlight, and to prevent sweat from running down to the user's face during climbing mountains or fishing.
If a light emitting device is mounted on a visor of the cap, the user's hands are set free, so that the user's freedom of activity is improved. In addition, the direction of the light emission can track the user's sight line, so that the user can better see.
To illustrate such advantages, the applicant of the present invention has filed “a light emitter to be attached to caps”, Korean Utility Model Registration No. 0312151, which corresponds to U.S. Pat. Nos. 7,118,241 and 7,163,309, and Canadian Patent No. 2,535,295.
FIG. 1 is a view representing a light emitter according to the related art.
As shown in FIG. 1, the conventional light emitter includes a case 22 forming a body, several lamps 24 installed at a front side of the case 22 while being spaced apart from each other, a switch member 26 installed at a side of the case 22, a battery incorporated in the case 22, and a clip 28 which is formed at an upper surface of the case 22 and has an end integrally coupled with the case 22 to elastically flex outwardly therefrom.
However, according to the related art, since the lamps installed at the front side of the case are simultaneously turned on or off by a single switch, the light emitter's ability to adjust the area or the amount of illumination, for example to save the battery, is limited.
Also, when the light emitter is carried in a knapsack or a pocket, the switch can be turned on regardless of the user's intention. In this case, the lamps may be turned on simultaneously, so that the battery may be discharged in contrast with the user's wishes.
In addition, since all of the lamps are fixedly directed toward the forward direction, if the user wants to change the direction of illumination, the user must turn his or her head to the intended direction.
Furthermore, in the case of short range illumination, a small quantity of light is required as compared to the quantity required for long range illumination. However, the conventional light emitter can not adjust the amount of emitted light according to the field to be illuminated.